The present invention relates to testing of wireless devices, and in particular, to testing of wireless signal transceivers in non-link testing modes to reduce test times and communications required between the tester and device under test (DUT) during testing.
Many of today's electronic devices use wireless signal technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless signal technologies must adhere to various wireless signal technology standard specifications.
When designing such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless signal technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless signal technology standard-based specifications.
Testing of such wireless devices typically involves testing of the receiving and transmitting subsystems of the device under test (DUT). The testing system will send a prescribed sequence of test data packet signals to a DUT, e.g., using different frequencies, power levels, and/or signal modulation techniques to determine if the DUT receiving subsystem is operating properly. Similarly, the DUT will send test data packet signals at a variety of frequencies, power levels, and/or modulation techniques for reception and processing by the testing system to determine if the DUT transmitting subsystem is operating properly.
For testing these devices following their manufacture and assembly, current wireless device test systems typically employ testing systems having various subsystems for providing test signals to each device under test (DUT) and analyzing signals received from each DUT. Some systems (often referred to as “testers”) include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the DUT, and a vector signal analyzer (VSA) for analyzing signals produced by the DUT. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable (e.g., through use of an internal programmable controller or an external programmable controller such as a personal computer) so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless signal technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
Ordinarily when testing a wireless device (e.g., a wireless fidelity (Wi-Fi), Bluetooth, Zigbee, Zwave or similar device) with a tester, once communications between tester and DUT have been established, the tester and DUT will execute a test flow during which the tester controls the behavior of the DUT by executing control commands via driver software associated with the DUT. Commands may include instructing the DUT to receive test packets from the tester, or to transmit packets to the tester. The characteristics of the packets may also be controlled, such as power level, frequency, data rate, modulation, etc.
Traditional methods of testing such devices are link-based, in which the tester interfaces the software stack of the DUT to establish a link as if the tester were a similar device. This approach can be advantageous inasmuch as it tests for software failures in addition to hardware failures and requires little if any code development for the tester to communicate with the DUT. In a production line, however, software tests are generally unnecessary, since target failures in such tests are due to manufacturing differences, which predominately affect only the hardware. Hence, the time needed to setup and teardown a connection (link) is essentially a wasted and costly resource.